package cn.wolfcode.trip.admin.filter;


import cn.wolfcode.trip.base.util.UploadUtil;
import org.apache.commons.io.FileUtils;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import java.io.File;
import java.io.IOException;

/**
 * 图片过滤器
 */
public class ImageFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) request;
        //获取图片的路径
        String uri = req.getRequestURI();
        //获取公共区域中的图片
        File file = new File(UploadUtil.PATH, uri);
        //判断是否存在
        if(file.exists()){
            //响应到浏览器
            ServletOutputStream outputStream = response.getOutputStream();
            //把文件转成Byte字节数组
            outputStream.write(FileUtils.readFileToByteArray(file));
        }else{
            //放行
            chain.doFilter(request,response);
        }
    }

    @Override
    public void destroy() {

    }
}
